The present disclosure relates generally to the manufacturing of semiconductor devices, and more particularly to utilizing an anti-reflective coating layer in semiconductor manufacturing.
During the manufacturing of semiconductor devices, substrate topography or non-uniform substrates may cause variations in exposure energy. As a result, certain regions of the photoresist that should be unexposed may become exposed unintentionally, resulting in notching of the photoresist.
One method for reducing such notching is to add non-bleaching dyes to the photoresist. However, such a method possesses a number of shortcomings. First, it may cause unintended resist sidewall angles. Second, in submicron technologies, the required high dye concentration may cause magnified standing wave near the photoresist-substrate interface, resulting in resist scumming.
Another method for reducing notching is to utilize an anti-reflective coating (ARC) layer. As a result, reflection from the substrate may be suppressed by attenuating light that passes through the ARC or by matching the refraction index of the ARC to that of the light. In practice, ARC layers may be deposited either on top of a photoresist layer to form a top anti-reflective coating (TARC) layer, or beneath the photoresist layer to form a bottom anti-reflective coating (BARC) layer.